Nonlocal effects in superfluid turbulence: Application to the low-density- to high-density-state transition and to vortex decay

Journal Article · Tue Mar 01 04:00:00 EST 2005 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.71.094507· OSTI ID:20666290

Mongiovi, M S ^[1]; Jou, D ^[2]

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1. Dipartimento di Metodi e Modelli Matematici, Universita di Palermo, Facolta di Ingegneria, Viale delle Scienze, 90128, Palermo (Italy)
2. Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia (Spain)

We discuss a phenomenological equation for the evolution of vortex tangle in counterflow superfluid turbulence, which takes into account the influence of the nonlocal effects, introducing into the original equation of Vinen two simple corrective terms dependent on a nonvanishing ratio between the average separation between vortex lines and the diameter of the channel. The equation allows one to describe, in relatively good agreement with experimental results, the two turbulent regimes present in counterflow superfluid turbulence and the transition between them. The decay rate of the vortex line density L, when the heat flux is suddenly turned off, is also investigated; due to the simplicity of the model, which does not take into account the coupling of the line density L with the superfluid velocity, this decay agrees with experiments in the initial and intermediate stages, but does not describe the full slow-down observed at very long times.

• OSTI ID: 20666290
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 9 Vol. 71; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COUPLING
DECAY
HEAT FLUX
HELIUM 4
SUPERFLUIDITY
TURBULENCE
VELOCITY
VORTICES